X0305 4 2012-05-01 0 0001121702 METABOLIX, INC. MBLX 0001377831 Muller Edward M C/O METABOLIX, INC. 21 ERIE STREET CAMBRIDGE MA 02139 1 0 0 0 Common Stock 2012-05-01 4 S 0 15000 2.6001 D 765091 D Represents the weighted average sale price for the shares sold. Sales prices for this transaction ranged from $2.47 to $2.75. The reporting person undertakes to provide, upon request by the Commission staff, the Issuer, or a security holder of the Issuer, full information regarding the number of shares sold at each separate price. /s/ Sarah P. Cecil, attorney-in-fact 2012-05-03